A conventional ratchet tool having an angle-adjustable head is disclosed in U.S. Pat. No. 6,216,567 and generally includes a pawl biased by a first spring so as to limit the pivotable movement of the head and a control member biased by a second spring such that when pushing the control member, the pawl is disengaged from the head which is able to be pivoted. Another conventional pivotable wrench is disclosed in U.S. Pat. No. 6,148,698 and generally includes two toothed lugs on the head and a control mechanism is received in a transverse passage in the handle. The control mechanism includes a shaft with two toothed sections for being matched with the two toothed lugs. Nevertheless, both of the two inventions include multiple number of tiny parts which make the assembly processes to be complicated and time consuming. Besides, many holes and recesses with stepped surfaces have to be drilled in the head or the handle so as to receive the parts and the head or the handle has only limited area for the drilling.
The present invention intends to provide a control mechanism that controls the position of the pivotable head relative to the head by a simple and reliable mechanism.